Reproducer for talking machines



May 27, 1924. 1,495,265

' c. scRABl REPRODUCER FOR rALKTNG MACHINES Filed June 13. 1919 2 Sheets-Sheet 1 May 27, 1924. 1,495,265

C. SCRABIC REPRODUCER FOR TALKING MACHINES Filed June 13 1919 2 Sheets-Sheet 2 Patented May 27, 1924.

UNITED CARL SCRABIC, OF URBANA, O'HIO.

REPRODUCER FOR TALKING IVJACI-IINES.v

Application filed June 13, 1919. Serial No. 303,951.

To all 'whom t may concern:

Be it known that CARL SCRABIC, a citizen of Czechoslovakia, a Republic, residing at Urbana, in the county of Champaign and State of Ohio, has invented certain new and useful Improvements in Reproducers for Talking Machines, of which the following is a specification.

This invention relates broadly to talking machines, and has particular reference to the reproducer structure thereof, the object of the invention being to provide a reproducer of simple and yet eiiicient construction, capable of being employed with records ofl standard manufacture and to be of a highly sensitive and accurately balanced character in order that the same may efliciently reproduce all of the sound undula- 'tions of a record in a clear, positive and pleasing manner.

To this end, the invention comtemplates the provision of a reproducer or sound box wherein is provided a casing having a pair of spaced diaphragms mounted therein, said diaphragms being connected by means of a cross rod with an oscillatory stylus member, the latter being mounted upon knife edges and constructed to carry the usual needle, this construction being such that the vibration of the stylus member will be uniformly and synchronously imparted to the diaphragms so that the latter will vibrate in unison and harmony, whereby the reco-rd undulations will be reproduced with marked clarity so that none of the tonal properties thereof will be sacriced but, on the contrary, will be enlarged and developed in proper varying degrees to render the various shades of tone distinctlyaudible.

With these and other objects in view, as will appear as the description proceeds, the invention accordingly consists in the novel features of construction, combination of elements and arrangement of parts, hereinafter to be fully described and to have the scope thereof pointed out in the appended claim.

In the accompanying drawings, forming a part of this specification, and in which similar characters of reference denote like and corresponding parts:

Figure 1 is a side elevation of a sound box constructed in accordance with the preferred principles o-f the invention.

Figure 2 is a transverse vertical sectional view taken through the sound box on the il plan disclosed by the line 2-2 of Figure 1.

Figure 3" is an edge elevations/of the sound box and disclosing the same as employed for playing the so called hill and dale7 type of record.

Figure 4 is a front elevation of a sound box with the parts positioned as shown in Figure 3.

Referring more particularly to the details of the invention, the sound box 1 comprising the present invention is employed in connection with the usual tone arm 2, the latter is provided with the usual goose neck construction 3 upon its forward end or 'at its point of attachment with the sound box, so that the latter may be readily positioned upon or removed from a record. It will of course be understood. that the tone arm may be of any other desired construction and may be associated in any yappropriate manner with the amplifying structure (not shown) of a talking machine. The sound box 1 in this instance consists of a. main casing 4, which is formed to provide side walls 5, a connecting eripheral wall G, offset peripheral flanges? and an axial bore 8. The latter is in communication with an upstanding internally situated sleeve 9 which has its walls spaced from the side walls 5 of the casing, a space 10 being delined therebetween. Entering this space is the tubularI end 11 of the connection 3 and the extent of inward movement of the end l1 into the space 10 is governed by means of an annular collar 12 formed upon the outer wall of the connection 3. To secure the casing 4 in swiveled relation with the connection 3, said casing is provided with. an upwardly disposed threaded portion, with which is associated a nut 13, the latter being provided with an annularly and inwardly bent flange 14 which is disposed to cooperate with the collar 12 of the connection 3. By virtue of this construction, it will be manifest that the casing 4 may be revolved about the connection 3 so that the sound box as a whole may be adapted to records of different manufacture. The extent of rotating movement of the sound box is governed by providing, in this instance, the nut 13 with a lug 15, which is disposed to cooperate with fixed stops 16 provided upon the connection 3, said stops being so disposed as to permit the sound yes box to rotate substantially throughout an arc of ninety degrees. Through the provision of the sleeve 9, the sound box is securely supported for rotatable movement about the connection 3 so that all looseness between parts will be eliminated and in this manner, extraneous vibration reduced.-

The lianges 7 of the casing are offset from the side walls 5 to provide diaphragm sockets 17 and in which soc iets are located a pair of transversely spaced diaphragme 18 formed from any suitable material. The peripheral edges of the diaphragme are mounted as usual between gaskets 19 and are secured in position by means of clamping rings 20, which are secured to the casing by means of screws or other fastening elements 21. This seating of the diaphragme is of course susceptible to modification, the structure being merely such as to permit the diaphragms to vibrate independently of the sound box structure. Rigidly connected with both of the diaphragms and extending through and beyond the bore 8 is a connecting rod 22 which has its outer ends rigidly secured to the stylus member 23. The member 23 preferably consists of a needle receiving base 24 which is located in vertical alignment with the sleeve 9 and is positioned centrally of the sound box. The base 24 terminates in curvilinear arms 25 which extend around the edges of the sound box and terminate contiguous to the connecting rod 22, to which the ends of said arms are secured. The base 24 is mounted for oscillatory movement upon a pair of knife edges 26 which are resiliently mounted as at 27 in order to place the stylus member under slight pressure so as to eliminate undue vibration or loose play. The base 24 is provided with a needle socket 28a, in which the usual needle 29 is' removably mounted by means of a thumb screw 30.

From the Jforegoing description, taken in connection with the accompanying drawing, it will be apparent that there is provided a sound box of considerable utility and one particularly capable of carrying out the objects of the invention. The sound box essentially is so constructed that the stylus member will have its point of oscillation spaced equidistantly from the diaphragms 18, so that the movement of the stylus member will be equally imparted to the diaphragms so that the sound waves created thereby will be of equal proportions. This structure is believed to be in contra-distinction to the method hitherto employed of locating the pivot point of the stylus member to one side of the diaphragms and has overcome the disadvantage found in the latter of creating different and foreign Vibrations in the spaced diaphragms.

I claim:

In a sound box for talking machines, a casing comprising a pair of transversely spaced walls, a sound conduit extending axially of said sound box and connecting said walls, a sleeve projecting upwardly from said conduit and disposed between said Walls, a tone arm connection including a vertically disposed tube having its lower end telescoped between said walls and sleeve, a collar provided on said tube, and a retaining ring connected with said casing and disposed to engage with said collar'to effect a rotatable connection between said sound box and tube.

1n testimony whereof 1 aHix my signature.

CARL SCRABTC. 

